I hurt my right knee about 4 to 5 years

Patient :I hurt my right knee about 4 to 5 years ago when I was running. I fell on it pretty hard, but nothing bad happened, except for a bad limp the following after. After that I got better. But, now when i run, my knee has a hollow pain, where the pain doesn't hurt bad, but it is lingering there. This has been going on for months. I was hoping the pain would go away, but it is not. I've changed shoes, I've ran at a slower pace. I've done everything so that the pain wouldn't stay. Could this be because of the injury from 5 years ago? Should I check with a doctor?
(Quick synopsis of injury: Was running. Tripped over a desk in the middle of hallway, right knee took impact of the fall. Happened in grade 7)

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